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It's that time of year again: bug time. The weather is warmer, we are outside more--and swatting at bugs. Which makes us think about...bug spray.

I get lots of questions at work about bug spray and kids. What's safe? What works? I've done some research, and here's what you need to know. This is a bit jam-packed with facts, sorry--but hopefully it's helpful!

The best repellent out there against both ticks and mosquitoes is DEET (N,N-diethyl-meta-toluamide). The smell of it really bums out insects--that's how it works. The length of protection depends on the percent of DEET--ten percent protects for a couple of hours, and 20 percent for about twice that.

There are possible side effects. The most common is skin irritation--you especially want to avoid spraying it on skin that is already irritated or scraped. There is also a very small risk that DEET can affect the brain, even causing seizures. According to the Environmental Protection Agency (EPA), the risk of seizure is about one in a hundred million users.

The American Academy of Pediatrics says that up to 30 percent DEET is safe in children, although they do not recommending using it in infants less than two months old. Interestingly, Health Canada doesn't recommend it for infants less than 6 months old, only recommends using up to ten percent and in general suggests using it only if necessary.

That's the thing--with any treatment, there is a risk-benefit ratio. If you are going to be somewhere with a lot of ticks, or health officials in your area are warning about mosquito-borne illnesses like West Nile or Eastern Equine Encephalitis, or you have a kid that routinely gets tons of bites that get inflamed, then DEET is probably a good idea (in parts of the world where there is malaria, it's definitely the way to go). But if not, or if you don't feel comfortable with the risks, there are other options.

While researching, I found a really great tool on the EPA website. You type in whether you want to protect against mosquitoes or ticks or both, for how long, and it will give you suggestions (including brand names, to make it easier) and tell you what the active ingredients are of each one. You can also search particular active ingredients and find out about particular products.

Here are some other repellents that work pretty well. I've linked to EPA information so you can read about side effects, but they are all minimal.

2-undecanone (IBI-246). This is a chemical naturally found in various plants--it's used to not only repel insects, but dogs and cats! It is found in Bite Blocker products. According to the EPA, it protects for four hours against mosquitoes, two hours against ticks.

Oil of Lemon Eucalyptus or PMD (the man-made version of it)--this works pretty well for up to six hours against both mosquitoes and ticks.

IR-3535--this is the active ingredient in Avon's insect repellents. It's made from a common amino acid, alanine. It only protects for about two hours against mosquitoes or ticks.

Citronella oil--doesn't work as well as Eucalyptus. You will only get an hour or so out of it.

Other oils, like Soybean or Catnip (your cat will love that one)--they offer variable protection, and aren't so great against ticks.

Here are some products and techniques that don't work:

Wristbands soaked in repellents (in one study I saw, they kept mosquitoes away for less than a minute).

Garlic or vitamin B1 taken by mouth

Bug zappers and ultrasonic devices (if only it were that easy!)

No matter what kind of repellent you use, remember:

Grownups, not kids, should do the applying.

Spray in an open area to minimize how much of the stuff you breathe in.

When applying to the face, spray some into your hand and then rub it on the face (steering clear of the eyes and mouth).

Wash your hands, so that you don't end up inadvertently mixing bug spray with your sandwich (this is why I'm not so wild about those repellent wipes).

Try to use a product geared for the amount of time you need, rather than reapplying (especially when using a DEET product).

Don't buy combination sunscreen-insect repellent products, for just this reason--sunscreen is something you should reapply.

Don't use it on open skin.

Dress kids in light-colored clothing--and spray the clothing.

Give kids a good washing at the end of the day with soap and water, and be sure to wash sprayed clothing before it's worn again.

Insect bites are part of life--we can't prevent every last one. But if we prevent a few, we lessen the risks of illness like Lyme Disease or West Nile. And (this is more important to our kids), we make summer a little less itchy.

This blog is not written or edited by Boston.com or the Boston Globe.
The author is solely responsible for the content.

About MD Mama

Claire McCarthy, M.D., is a pediatrician and Medical Communications Editor at Boston Children's Hospital . An assistant professor of pediatrics at Harvard Medical School and a senior editor for Harvard
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